UNCLASSIFIED NALYTICAL PRCCEDURE FOR TEE SEPARATION OF nortt R DIOSTROMTTIM FROM =< $2425 OF ROME ASH. Ash the tone sample in nickel crucible at 900° C Grind in a mortar to a fine sender. Weigh out 5 grams into a 250 ml centrifuge bottle. Add 4h ml cf water and then slowly add 154 ml of 90% nitric acid to bring concentration te 75% HNO3. Add 20 mg of Sr carrier (as Sr(NO3)a) in 2 ml of solution. Stir rapidly for thirty minutes. (Mechanically) Decant, dissolve the precivitate in 23 ml of water and t + 42) 4 Centrifuge for 10 minutes at about 2000 r.p.m. to a 25C ml beaker, add slowly 77 ml of 90% HNC, and stir mechanically for thirty minutes. Filter through a fluorothene funnel on to a elass fiber filt Transfer the funnel to a clean filter flask and wash the aci from the precipitate with anhydreus ethyl ether. Place the filter caver on a brass disc-and=ring assembly The glass ficer filters are avail: from H, Reeve Angel and Co., Inc., $2 Duane Street , New Yark N, ¥., as catalog number X+-9 3u-AH Trav gre more retentive oaper filters and imservious to 73% HNO3. Am3 UNCLASSIFIED iD sounti ng on filter vaner. f~rs Note: The fluorothene funnels are a modification cf the Tracer tainless steel funnel, designed for oreva ring preciritates TF (Tracerlab), cover with 0.001 inch nliofilm and J count. 7 OE.